Abstract
This research was conducted to make clear the characteristics of run up of fish in the small model full cross fish way with rubble stones. The efficiency of fish way depends on the structure (shape, bottom slope, rubble size), hydraulics (velocity, depth, turbulence).At first, Authors clarified the relation between the run up ratio and flow condition; Namely, 1) as discharge becomes bigger, velocity increases over than the limit of the swimming capability, run up ratio becomes lower consequently, 2) in the case of longer fish way, the run up ratio becomes lower since fish can not keep the maximum swimming speed (burst speed) for so long time.Next, authors consider the improvement the run up ratio by adding pocket or flat space with rubbles damping the velocity on the way of fish way.Finally, a research was conducted the effectivity in the situation that a part of fish ways were broken.
